1. Field of the Invention
The present invention generally relates to a lancing device for withdrawing a blood sample for medical treatment, and more particularly, to an automatic lancing device obtaining a blood sample exactly at a desired position without misoperation and adjusting the penetration length of lancet according to depth of the skin.
2. Description of the Prior Art
Generally, a lancing device is used when a small amount of blood is needed in medical treatment procedures, such as blood type test or blood sugar test.
In the conventional lancing device, as shown in FIG. 5, a lancet (not shown) receiving an elasticity generated by an elastic member, such as spring (not shown), is mounted within a case 50. The lancet is automatically ejected from the front end of the case 50 by means of elasticity of the elastic member, thereby piercing the skin at a predetermined depth. The lancing device elongates the elastic member positioned at the inside of the case 50 by moving an operating member 52 positioned at a back end of the case 50 to the rear. A pushing member 51 is formed to protrude from one side of the case 50. When the protruded pushing member is pushed, the spring is contracted and generates the elasticity. By means of the said elasticity, The lancet is ejected from the front of the case, thereby piercing the skin. After the lancet pierces the skin, the elastic member retracts the lancet to a safe position within the lancing device.
However, the ejection length of the lancet in conventional the lancing device cannot be regulated. As a result, in order to obtain blood sample at the skin having different depth, a lancing device comprising a lancet having a different ejection length should be used. Furthermore, because the pushing member 51 generating instant impact to the lancet is located at one side of the case 50, a user happens to push the pushing member 51 by mistake when seizing the case 50, thereby piercing an undesired place of the skin.